(1) Field of Invention
The present invention relates to a series of novel silicone derivatives of taurine having a fatty amido group present within the molecule. These materials are surface active silicone compounds which are useful in a personal care and related applications.
Since the compounds of the present invention are high molecular weight silicone polymers, they have a high degree of oxidative stability, even at elevated temperatures. In addition, these compounds are non volatile and non irritating to eyes and skin.
The compounds of the present invention are prepared by the reaction of a carboxy silicone with taurine.
(2) Object of the Invention
It is the object of the present invention to provide a series of novel silicone amido taurine polymers, which are substantive to skin and hair and useful in making soap bars.
This substantivity results in superior softening, conditioning and antistatic properties and results in a slick feeling soap bar.
It is another objective of the current invention to provide an amido silicone taurine derivatives which are nonirritating surface active agents. The compounds of the present invention have very low irritation values when applied to skin and eyes. Irritation is a major problem with traditional surfactants.
Application of the compounds of the invention can be from solvent, aqueous dispersion or solution, or applied neat in these process. It is anticipated that the effective conditioning concentration of the compound of this invention ranges from 0.1% to 25% by weight.
(3) Description of the Arts and Practices
Silicone oils (polydimethylsiloxane) have been known to be active at the surface of plastic, cellulosic and synthetic fibers as well as paper. Despite the fact that they are lubricants that are stable to oxidation, their high cost and lack of durability has made them cost prohibitive in most application areas. Silicone oils need to be emulsified prior to application. This requires high pressure equipment, surface active agents and generally results in a milky emulsion. Emulsions have experienced stability problems both in terms of freeze thaw instability and upon heating. This has resulted in minimal acceptance of them in commercial products.
The low efficiency of silicone oils is due to the fact that the oil is very water insoluble. Emulsions are generally prepared which contain silicone dispersed in micelles. While this method of application is easier for processing, much of the oil stays in the surfactant micelle and never gets deposited on the fiber. That which does deposit on the fiber surface remains there by hydrophobic binding, not ionic bonding. Since the polydimethylsiloxane is not bonded the effect is very transient. The product is removed with one washing. Taurine derivatives are known to those skilled in the art. Taurine conforms to the following structure: EQU R--N--(CH.sub.2).sub.2 --SO3 M
wherein R is alkyl, and M is a metal ion preferably an alkali metal such as sodium, potassium, ammonium or lithium.
None of the above incorporate silicone into compound. Consequently, the unique softening and substantivity properties achieved using the compounds of the present invention are not realized with the above technologies.